(1) Field of the Invention
The present invention relates to a laser-scanning microscope with sample illumination and detector means, which for the purpose of image acquisition illuminates and detects a sample in a raster scanning manner, with a real-time control device. The control device controls the illumination and detector means for illumination and detection and reads out detection signals, whereby the control device performs control and readout synchronously with a pixel cycle that determines the raster scanning. A data port is connected between the control device and the illumination and detector means and communicates with the control device via a parallel, bidirectional data stream and with the illumination and detector means via a serial, bidirectional high-speed data stream and for this reason performs a conversion of data from parallel into serial or vice versa.
The invention further relates to a laser scanning microscope with sample illumination and detector means, which for purposes of image acquisition illuminate and detect a sample by raster scanning, with a real-time control device, which controls the illumination and detector means for illumination and detection and reads out detection signals. A control device controls the illumination and detection and reads out the detection signals synchronously with a pixel cycle that determines the raster scanning, a data port, connected between the control device and the illumination and detector means, communicates with the control device via a parallel, bidirectional data stream and with the illumination and detector means via a serial, bidirectional high-speed data stream and for this purpose performs a conversion of data from parallel into serial or vice versa.
In a laser scanning microscope of this type, as is offered, for example, by Carl Zeiss AG under the designation LSM 510, image acquisition is carried out by exciting and scanning a sample pixel-by-pixel with excitation or illumination radiation. The image comes about by the intensity of radiation being allocated to the appropriate pixel coordinates and in this way coalescing into an image. Consequently, a pixel-synchronous matching of illumination and detector means, particularly of a scanner, i.e., of a deflecting device is required for illumination and detection in order to gather the information for the image. This implies that the highest data transmission rate possible should be used in the control as well as the readout of it since the speed and volume of the data transmission automatically impacts the length of time that is needed for imaging. Especially with biological samples, it would be desirable, though, to obtain an image as fast as possible, for example, to be able to analyze biological processes. At the same time, this is not only dependent on the data rate, i.e., the product of the data packet size and transmission frequency, but also on the reaction speed at which communication proceeds between the real-time control device and the illumination and detector means. The transmission frequency is a determining factor for this.
Here it must also be borne in mind that not only the control of the deflecting device or the illumination units, e.g., lasers, etc., has to be carried out in a pixel-synchronous way, but rather that today's highly sensitive detector means require equally to a certain extent complex control for readout of the intensity of radiation to be allocated to the pixels. Photomultiplier tubes (PMTs) requiring among other things control of the radiation integration procedures and readout processes are cited as an example. For each pixel, data has to be transmitted to the PMT and data also has to be read out by the PMT. In the final analysis, therefore, an effort is being made to design the data communication so fast that it is not the time determinant in the operation chain. This implies that the data communication should be fast enough in order to process the data traffic needed for this within the minimum time that is needed for detection of a pixel's radiation by the detector (which is called the pixel time).
For high-speed data communication different approaches, which however either need substantial device-related time and effort or have insufficient speed attainment, are familiar in data processing technology.
(2) Summary of the Invention
Therefore, the present invention's basic function is to refine a microscope or technique of the type designated at the beginning in such a way that control of the illumination and detector means is achieved with little time and effort. At the same time, the data rate attained allows for transmitting the data required for each pixel within the pixel time specified on the detector side.
According to the invention this function is performed with a laser-scanning microscope of the designated type, in which the high-speed data stream from the illumination and detector means to the data port is made up of data packets with data bits and type bits and with no additional header or protocol bits. The data bits contain the data on the illumination and detector means and the type bits code the type of data. In the illumination and detector means, if need be, also in the control device, type information is stored that defines processing functions for data types coded by means of the type bits, and when sending, the illumination and detector means set the type bits for the data types in a type assessment. The function is performed further with a technique of the designated type, in which the high-speed data stream between the illumination and detector means and the data port is made up of data packets with data bits and type bits and with no additional header or protocol bits. The data bits contain data from the illumination and detector means and the type bits code the type of data. In the illumination and detector means and the control device, type information is stored that relates to processing functions for data types coded by means of the data bits, and, when sending the illumination and detector means and/or the control device, set the type bits for the data type in a type specification and the control device and/or the illumination and detector means defines the data types using the type bits in a type assessment and process the data coded in the data bits accordingly.
According to the invention header or protocol data, as they are used in usual high-speed data systems (e.g. FireWire or USB) with serial communication and as they usually occur in a normal parallel-to-serial conversion, are dispensed with for the transmission of illumination and detector means. Therefore, a header no longer exists in the data packet as to, e.g., who is sending the data to which address in the bus they are directed, what can be done in case of error handling, etc. From the illumination and detector means to the control device, the data stream is made up exclusively of data bits and type bits, whereas the latter code information on the type of data stored in the data bits. Each module attached to the link carrying the data stream thus makes a type bit specification when delivering the data. The type bits are distinguishable from header bits of normal communications data streams by the fact that they contain no general information, but rather merely provide information on the processing of the data in the data bits which are to be subjected to in combination with type indications, which are authorized at the sending and receiving end, and the type assessment based on this at the receiving end.
The high-speed data stream consequently is adjusted in a microscope-specific way and as a rule requires stored type information both on the receiving and sending end as to how the data are to be arranged or processed. This type of data communication, on the one hand, manages to eliminate any redundant information and thereby increases the effective useful rate for the data to be transmitted. On the other hand, it simplifies the data-related time and effort on the sending and receiving end, since the type specification can be designed very simply with the senders or recipients using type bits. This immediately gives the recipients the necessary information as to whether and, if need be, how they have to process data bits, or whether not at all. At the same time the senders do not have to administer and communicate address data.
The invention-related conversion of the parallel, bidirectional data stream into a serial, bidirectional high-speed data stream, which is adapted to the requirements in the laser scanning microscope, further simplifies cabling in the microscope, since serial data cables need less space. In addition, a standard computer can be used for the real-time control device, and complex or costly special interfaces on the part of the real-time control device are left out. The conversion into/from the microscope-specific high-speed data stream first takes place at the data port that acts as the microscope's port.
The invention-related concept for communication from the illumination and detector means to the control device is indeed particularly advantageous; however, a use in the reverse channel, which is located away from the control device, is equally possible.
The utilization of high-speed data transmission with type bits has the added advantage that every data packet made up of data bits and type bits can now simultaneously be sent out or also received by multiple illumination and detector means' positions if for example the type assessment for a type of data reveals that it is relevant at different locations, e.g., by different illumination and detector means' units. With traditional address-based data communications, a simultaneous broadcasting of a data packet from and/or to different units would be impossible and instead of that multiple data packets would have to be furnished with different addresses and transmission delayed via the high-speed data stream. It is easily understandable that the useful data transmission rate achieved then would be reduced a number of times.
Usually laser-scanning microscopes are broken down into individual modules, which act together in the illumination and scanning. Various illumination modules, which can be integrated into a microscope and provide radiation of various wavelengths, are an example of this. It is also a familiar practice to equip laser-scanning microscopes with different detector modules, which have, e.g., different spectral analysis capabilities. For such a modular design, it is desirable to provide a data manager to communicate with the individual modules and to connect to the individual modules according to the serial high-speed data stream, since the individual modules must be operated in coordination with each other, however, for the most part individually do not need the full data rate for communication; this data rate is only necessary in the interaction of all the modules on the part of a real-time control device.
It is naturally advantageous for this design to make up the individual serial streams (which, e.g., can be designed pursuant to familiar LVDS data transmission) of data bits and types bits as well and dispensing with additional header bits between the individual modules and the data manager, since otherwise address and header information would have to be created and also transmitted by the individual modules. It will be more practical for the data manager to have the appropriate connectors for the individual modules. The data manager continues to work better with a fixed allocation scheme, by which it feeds the individual modules' data packets into the high-speed data stream. A time-consuming analysis of the individual data streams in the data manager or one requiring a processing unit is not necessary then, yet the real-time control device or the data port has to take into consideration the consolidation of the high-speed data stream from the individual data streams that is permanently set in the data manager, i.e., the individual data streams' data packets will be arranged by the data port or the real-time control device accordingly in the high-speed data stream in such a way that the allocation in the data manager is reflected in the structure of the high-speed data stream.
Since a modularly designed laser scanning microscope is only seldom changed or in the case of redesign fixed connection regulations can be preset, this limitation does not constitute a hindrance. In addition, if need be, or as an alternative at the data port and/or in the real-time control device, a setting mechanism (e.g., as software or hardware device) can be provided, through which it and/or they are communicated to the individual modules that are bound to the individual data stream connectors so that the data port or the control device knows how the data packets in the high-speed data stream are composed of the individual data streams.
For this reason, for a modular microscope it is advantageously provided that the illumination and detector means have multiple individual modules, which interact during the illumination and scanning, a data manager communicating with the individual modules and merging the high-speed data stream from individual serial streams of the individual modules and leading it out of the data port is connected between the data port and the individual modules of the illumination and detector means. The individual serial data streams between the data manager and individual modules are also made up of data bits and type bits and dispensing with additional header bits, the type information is stored in the individual modules and the individual modules perform the type assessment and the processing of the data coded in the data bits. Of course, this concept can also be used in direction of communication from the real-time control to the individual modules.
The data manager's work is especially simple if the individual data streams are carrying data packets that are a fraction as long as the high-speed data stream's data packets. Preferably, the individual data streams' data packets are half as long as those of the high-speed data stream. Then the data manager simply composes each high-speed data stream data packet from two halves that are derived from two individual data streams. The data packet frequency of each individual data stream is then equal in size to that of the high-speed data stream, however with half the packet length. Half the frequency of the high-speed data stream is sufficient for an individual module, the data manager can make up each packet of the high-speed data stream alternatively separately from two individual data streams so that overall four individual data streams are used, which in each case have half the frequency of the high-speed data stream and half the packet length. The one high-speed data stream is then simply composed of four individual data streams. This is naturally also possible with simultaneous sending out (broadcast) of the individual data packets.
In the same way, naturally, scaling is possible, i.e., two different data ports or a double data port can be provided which convert(s) the parallel data stream from the real-time data control device into two high-speed data streams. This can be practical in very complex laser-scanning microscopes.
If it would be desirable to address numerous individual modules, it can be even more advantageous that multiple individual modules are connected to a single common data link and utilize this data link as a type of a data bus, whereas the type assessment in turn implicitly defines which individual module or which individual modules process or in the case of transmission send out a data packet's data that are coded in the data bits.
In laser-scanning microscopes, the illumination and detector means also have actuators, which for the most part have a call back function to the control unit and which can be suited or set for operation without any impact occurring in the pixel cycle or shift being necessary, aside from elements to be controlled in a pixel-synchronous way. The pinhole shift mechanical data before the detectors are examples of such actuators. Other examples are the setting of drivers for acoustic-optical filters in illumination units, the drives for color distribution switchers or shutters, and safety screens or the like. All such components do have to have a certain setting during operation of the laser-scanning microscope, yet an activation and/or call back report occurring in the pixel cycle is unnecessary. Usually, such actuators have so far been controlled with slow working data busses, e.g., what is called a CAN bus, which implies that in traditional microscopes a (non-pixel-synchronous) slower (CAN) bus has to still be carried through the entire device along with the high-speed data communication.
In the invention-related laser-scanning microscope, it is now possible to make separate settings data bus networking of the entire microscope unnecessary by embedding into the high-speed data stream with a certain type coding the settings data or callback data, which for example are added to the units according to the CAN bus protocol just mentioned, and by having the illumination and detector means extract from the high-speed data stream the settings data or the data port, the data manager or the control unit the reverse data using the type coding carried out by the respective transmitter and leading them to the actuators or processing them.
The slow and not necessarily pixel-synchronous settings data, therefore, are fed into the high-speed data stream from the real-time control device or the data port and extracted on the receiving end, i.e. in the illumination and detector means. The opposite applies to reverse data. For this reason, it is provided in a preferable refinement of the microscope that the illumination and detector means have settings elements, which can be controlled when the microscope is in operation asynchronously to the pixel cycle, whereas the control device makes the suitable settings data for the settings elements, the settings elements are embedded, e.g., with a certain type coding or address into the high-speed data stream and the illumination and detector means extract the settings data and lead them to the settings elements. Alternatively or in addition this is carried out in the reverse channel.
The CAN bus that was already mentioned is an efficient implementation for the forwarding of settings data to the settings elements. For this reason, it is provided for in a refinement that at least one individual module will make available a CAN bus for at least one settings element allocated to the individual module or provided for in it and will convert the settings data and/or reverse data into and/or from the CAN bus data by means of a converting element.
In order to test the settings elements, which are controlled, e.g., via the CAN bus, usually full operation of the microscope is necessary, since all actuators are connected to a common CAN bus system. The invention-related design, in which the settings data are converted from and/or into the high-speed data stream from the illumination and detector means, i.e. usually from the individual modules, now allows for a design, in which the individual modules or individual components of the illumination-detector means can be tested individually. For this a diagnostic connector to the CAN bus is provided for in the individual module through which a direct CAN bus control of the settings element is possible for diagnostic and checking purposes. The diagnostic connector is therefore located between the converting element that converts the settings data from and/or into the high-speed data stream and the settings element. In that way it is possible to check the functionality of a settings element individually without having the rest of the microscope in operation.
A more extensive check is possible if the converting element, which makes available, e.g., the CAN bus data, also performs a reverse conversion of the settings data into the serial data stream. Then the interaction between the control device and the individual module or its settings element can also be checked, since the control device obtains values fed in or presetting done by means of a reverse conversion at the diagnostic connector. The forward and reverse conversion in each case can be provided for, not only, individually, but also in combination.
The use of individual data streams, as already mentioned, allows for a simple linking of different modules, whereas at the same time an unnecessarily high data rate is avoided on individual modules and the overall transmission rate of the high-speed data stream is distributed accordingly over the individual modules. Now the data manager can be designed in such a way that it will make an individual data stream available for each individual module. Alternatively, a option is presented whereby at least one of the individual modules has an outlet, to which it transfers the individual data stream introduced and assessed by it and through which an additional individual module is supplied.
This individual data stream, therefore, is used as a data bus, whereas the length of the chain essentially is only limited by the transit time of the signals up to the last individual module and the data rate made available by the individual data stream. Such an individual data stream bus can be utilized particularly well if individual data modules are combined in it, which modules require varying data rates in both communication directions. Therefore, individual modules with a high upload rate will be more beneficially combined with individual modules that need a high download rate. In turn, naturally settings can be made at the control device or at the data port and consideration can be given to how the individual modules are linked to the individual data streams. In this way, the data manager simply can execute a segmentation and/or combination of the high-speed data stream into and/or out of the individual data stream(s). In other words, the high-speed data stream in its composition reflects the segmentation and/or combination of the individual data streams' data packets that is carried out in the data manager and how the individual modules are linked onto the individual data streams, i.e., which one of the individual data streams a certain individual module will receive.
As far as the invention here is described with reference to a mechanism or a technique, this applies accordingly to the invention-related technique or mechanism, even if this matching of mechanism and technique characteristics should not be expressly mentioned.
Furthermore, the attached Table 1 shows an example of data conversion of the microscope in FIG. 1.